Field of the Invention
The present invention relates to a method for analyzing a positional displacement between head modules, a method for adjusting a recording head, and an image recording apparatus.
Description of the Related Art
In a field of inkjet drawing, in order to attain a high drawing resolution and high productivity, a head module having many nozzles two-dimensionally arrayed thereon is formed, a plurality of head modules are aligned in a recording medium width direction to form a long head (full-line type head) which covers an area to be drawn of an entire width of the recording medium. There has been known an inkjet drawing technique for forming an image on a recording surface of the recording medium by relatively scanning the recording medium one time in a direction vertical to a width direction of this long head (single-pass printing).
The long head having a plurality of head modules aligned thereon in this way has had a problem that unless head modules joining is carried out with high accuracy, nozzle intervals in the width direction are differentiated at a portion joining the head modules to deteriorate the quality of a formed image.
To deal with such a problem, Japanese Patent Application Laid-Open No. 2014-083720 discloses that in a method for analyzing a positional displacement between head modules of an inkjet head in which a plurality of head modules are connected and joined, by dividing a printing pattern by means of the head module to create division patterns, determining a conversion factor for each nozzle of the division pattern, and changing the number of nozzles used for calculation, a minimum value of a standard error of a between-modules depositing positional displacement shift amount between the head modules is determined, the number of divisions of the division patterns is changed, calculation of the conversion factor and calculation of the standard error are repeatedly carried out with the division pattern after the changing to determine the number of divisions and the number of nozzles where a value of the standard error is minimum.
According to this technology, since the number of divisions and number of nozzles of the printing pattern where the standard error is smaller are determined in advance to determine the between-modules depositing positional displacement shift amount between the head modules, an accuracy of the between-modules depositing positional displacement shift amount can be improved.